Natural TMEM145 GPCR inhibitors enhancing clothianidin susceptibility in Nilaparvata lugens.

While G protein-coupled receptors (GPCRs) are recognized as key upstream regulators of insecticide resistance in various agricultural pests, effective strategies to exploit these receptors for practical pest control remain largely undeveloped. In this study, we screened and identified TMEM145 as a novel GPCR significantly upregulated in clothianidin resistant Nilaparvata lugens. RNAi-mediated knockdown of TMEM145 suppressed the expression of the detoxification gene CYP6ER1 and the transcription factor AP-1, successfully restoring clothianidin susceptibility with a lethal dose ratio (LCR50) of 1.78. Through structure-based virtual screening of 4000 bioactive molecules targeting TMEM145, we mined pectolinarin as a potential inhibitor exhibiting a high binding affinity of -10.945 kcal/mol. Its structural scaffold, apigenin, was identified as an alternative with a binding affinity of -8.223 kcal/mol. Experimental validation confirmed that chemical inhibition by these flavonoids significantly downregulated detoxification gene expression. In vivo bioassays demonstrated that pectolinarin markedly increased clothianidin susceptibility, achieving a synergistic effect with an LCR50 of 2.87. These results demonstrate that targeting upstream GPCR-mediated regulatory nodes with natural synergists offers a promising and sustainable approach to managing metabolic resistance in agricultural pests.